Common Java Cookbook

Edition: 0.19

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4.1. Obtaining Commons Collections

4.1.1. Problem

You need to use Commons Collections because your system could benefit from the various functor interfaces and implementations provided by this component.

4.1.2. Solution

To use Commons Collections 3.2.1 in a Maven 2 project, add the following dependency to your project's pom.xml:

Example 4.1. Adding a Dependency on Commons Collections

    <dependency>
      <groupId>commons-collections</groupId>
      <artifactId>commons-collections</artifactId>
      <version>3.2.1</version>
    </dependency>  

If you are not sure what this means, I'd suggest reading Maven: The Definitive Guide. When you depend on a library in Maven 2, all you need to do is add the dependency groupId, artifactId, and version to your project's dependencies. Once you do this, Maven 2 will download the dependency and make it available on your project's classpath.

4.1.3. Discussion

Commons Collections was introduced as a series of utilities that augment the Java Collections API. Commons Collections contains functors such as Predicate and Closure, utilities for filtering and selecting elements in a collection, and some new collections: Bag and Buffer. Commons Collections is as widely used as Commons BeanUtils and Commons Lang, and with these two projects, it forms the core of the Apache Commons components.

4.1.4. See Also

For more information about the Commons Collections project, see the project page at http://commons.apache.org/collections.


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Common Java Cookbook by Tim O'Brien is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 United States License.
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